B737 Max faces newer and newer problems, Boeing desperate to find fixes

Boeing's once-bestselling B737 Max continues to be hounded by problems. The plane, which was banned globally for a record 20 months following two fatal crashes in quick succession, had to be grounded again by some airlines and dozens of flights had to be cancelled following another technical issue. The US plane making giant is said to be working on possible fixes as the new issue has become wider. 

The suspension on the B737 Max was lifted by the US aviation regulator Federal Aviation Administration (FAA) in November last year, followed by a similar easing of restrictions by some of the other regulators, notably those in Brazil, Europe, Canada and the UK, though China, which is the biggest market for the Max, continues to keep the plane off the skies. India has granted the aircraft only a limited right to operate. 

Still, following green signals from their respective regulators, as many as 20 countries had brought the Max back, but the aircraft's return suffered a jolt on April 9 when dozens of airlines had to pull the plane back from service after Boeing warned of a possible electrical insulation fault in the recent models that were produced, according to a Reuters report. Thankfully, however, the new issue is not as big as that associated with the Manoeuvring Characteristics Augmentation System (MCAS) that caused two crashes in 2018-19 killing 346 people.  

Also read: Boeing's fault-prone 737 Max can be flown over India, but not by Indian carriers

The latest problem is said to involve the electrical grounding -- or connections designed to maintain safety in case of a surge in voltage -- inside a backup power control system located in the cockpit. The issue is related to a change in material used for insulation once the production of the planes resumed in December last year. 

SpiceJet is India's biggest operator of the B737 Max. Image courtesy: Youtube

Later this month (April 2021), similar grounding flaws were found in two other places in the B737 Max cockpit, Reuters reported. These places include the storage rack where the affected backup power control unit is kept and the instrument panel facing the pilots. According to the FAA, Boeing's investigation showed that the electrical problem could impact the standby power control unit, a circuit breaker panel and the main instrument panel.

Around 450 B737 Max planes had been delivered since the aircraft first entered service, according to data up to the end of February 2021, Reuters reported. However, no deliveries of the Max planes were made after the electrical problem was detected. Nearly all the affected aircraft were built before deliveries resumed following the FAA waiver last year. 

The FAA said on April 22 that a total of 106 B737 Max planes, including 71 registered in the US, have been grounded in the wake of the electrical issue, and Boeing is still working on a solution.

Also read -- Boeing's B737 Max: Tragic hero for some, untouchable for others

Apart from the top three US B737 Max operators, namely Southwest Airlines, American Airlines and United Airlines, other carriers affected were Cayman Airways, Copa Airlines, GOL Linhas Aereas, Iceland Air, Minsheng Leasing, Neos Air, Shandong Airlines, SilkAir, SpiceJet, Sunwing Airlines, TUI, Turkish Airlines, Valla Jets Limited, WestJet Airlines and Xiamen Airlines. UAE-based budget carrier FlyDubai, however, said that its Max planes did not face the new issue. 

The B737 Max was banned all over the world in March 2019 following two crashes that killed nearly 350 people. First, a Lion Air B737 Max 8 en route from Jakarta's Soekarno–Hatta International Airport to Depati Amir Airport in Pangkal Pinang on October 29, 2018, crashed into the Java Sea 13 minutes after takeoff, killing all 189 people on board. Then on March 10, 2019, an Ethiopian Airlines flight operating the same type of aircraft, flying from the Addis Ababa Bole International Airport in Ethiopia to the Jomo Kenyatta International Airport in Nairobi, Kenya, crashed six minutes after takeoff, killing all 157 people aboard.

The aircraft's stall-prevention system called MCAS was blamed by the investigators for both the crashes. 

United Airlines is one of the carriers hit by the new technical issue in the B737 Max. Image courtesy: Wikimedia Commons/Konstantin von Wedelstaedt

The MCAS is a safety system installed on the B737 Max to control the plane's tendency to tilt nose-up because of the size and placement of the engines, a Live Mint report had pointed out. It repeatedly shoves the nose of the plane down if the plane perceives it is in a stall.

In both the crashes, erroneous sensor data triggered the MCAS and strongly pushed the nose of the plane down so much so that it went out of the pilots' control, sending the nearly brand-new jets into deadly plunges.

The grounding of the B737 Max had caused immense damage to Boeing. Image courtesy: Boeing

The MCAS was subsequently altered to prevent it from getting repeatedly activated and was re-engineered to limit how sharply the aircraft can dive. Redesigning of the plane’s flight-control computer was done to improve redundancy as well. According to Boeing, other fixes included updating pilot training manuals and cockpit safety alert as standard to show if the second angle of attack sensor displays a different reading and newer models were planned to get an extra sensor.

According to an article in Plane Vanilla, the FAA had estimated that there could have been 15 more crashes during the lifetime of the B737 Max if the MCAS was not fixed.

Although the electrical issue is nowhere as major as that involving the stall-prevention system, Boeing's reaction showed how much is riding on the Max returning to the skies. According to Reuters sources, after the issue was disclosed on April 7, Boeing rushed to brief staff, regulators, and airlines about the issue.

Also read: 'For SpiceJet, Boeing B737 Max's ungrounding makes no difference yet'

Boeing is apparently keen to gain back its credibility that was dented following its defensive reaction over the MCAS issue and complaints from flight crews that they were kept in the dark about changes to the new planes that were effected before they were delivered. It also underlines the importance of the fuel-efficient B737 Max in helping Boeing recover from a crippling coronavirus crisis.      

India's low-cost carrier SpiceJet is the biggest Max operator in the country with 13 such planes in its fleet. A Times of India report had pointed out that the airline had 200 more B737 Max planes on order. Jet Airways was the first airline to start B737 Max service in India and used to operate five such planes when it folded its wings in April 2019. The Jet Airways planes continue to be grounded due to the non-payment of lessor dues. 

According to FAA, the production issue "is not related to recertification of the flight control system on the 737 MAX, ungrounding of the aircraft, or its return to service".   

The US planemaker had planned to ramp up production of its cash cow B737 Max from an unspecified "low rate" at present to 31 per month by early 2022. According to industry sources, Boeing currently produces around four Max planes every month.

(Cover image courtesy Wikimedia Commons/pjs2005)